SIGGRAPH Asia

The call for submissions for SIGGRAPH Asia 2011 has recently gone live. This fourth iteration of the SIGGRAPH Asia conference will take place in Hong Kong between December 12th and 15th. In previous years, the sketches and course programs have been of similar quality (if reduced quantity) compared to their North American counterparts. The SIGGRAPH Asia Technical Papers have been really good, better in my opinion than the relatively abstruse SIGGRAPH Technical Papers. If you want to see for yourself, the incomparable Ke-Sen Huang has your back, with paper link pages for SIGGRAPH Asia 2008, 2009 and 2010. Ke-Sen deserves an outstanding service award from ACM, instead of the more negative attentions he has received from them.

Here is the 2011 CFS text (a slightly more detailed version can be found here):

Submit your research, theories, and innovations and you might be the next to have the valuable opportunity to present your work to audience-packed halls at SIGGRAPH Asia 2011 conference in Hong Kong this December.

The Real-Time Rendering paper session is, of course, most likely to contain papers of interest to readers of this blog. The most interesting paper, Micro-Rendering for Scalable, Parallel Final Gathering, was already discussed in a previous blog post. Since then, I’ve noticed many similarities between the technique described in this paper and the point-based color bleeding techniquePixar implemented in RenderMan. This approach to GPU-accelerated global illumination looks very promising. The other three papers in the session are also of interest: Depth-of-Field Rendering with Multiview Synthesis describes a depth-of-field method which occupies an interesting middle ground between the very high quality (and expensive) multiview methods used in film production and the much cheaper (but low-quality) post-processing methods commonly used in games; after some scaling down and optimizing, it may be appropriate for some real-time applications. Similarly to reprojection papers discussedpreviously, the Amortized Supersampling paper reprojects samples from previous frames to increase quality. Here the goal is anti-aliasing procedural shaders, but the technique could be applied to other types of expensive shaders. The remaining paper from the Real-Time Rendering session, All-Frequency Rendering With Dynamic, Spatially Varying Reflectance, does not yet have a preprint. The short abstract from the conference page does sound intriguing: “A technique for real-time rendering of dynamic, spatially varying BRDFs with all-frequency shadows from environmental and point lights”. Hopefully a preprint will become available soon.

I typically don’t pay very close attention to offline rendering papers, but one in particular looks interesting: Adaptive Wavelet Rendering takes a novel approach to Monte-Carlo ray tracing by rendering into an image-space wavelet basis, instead of rendering into image pixels or samples. This enables them to significantly reduce the number os samples required in certain cases.

The paper Continuity Mapping for Multi-Chart Textures attempts to solve a problem of interest (fixing filtering discontinuities at UV chart seams) but the solution is overly complex for most applications. While the authors claim to address MIP-mapping, their solution does not work well with trilinear filtering since their data structures need to be accessed separately for each MIP-map level and the results blended. They also do not address issues relating to derivative computation. Since their technique requires lots of divergent branching, it is likely to run at low efficiency. This technique might make sense for some specialized applications, but I don’t expect to see it being used for game texture filtering.

There are also some interesting papers on non-rendering topics such as animation and model acquisition. All in all, a very strong papers program this year.

A partial papers list has been up on Ke-Sen Huang’s SIGGRAPH Asia 2009 page for a while now, but I was waiting until either the full list was up or an interesting preprint appeared before mentioning it. Well, the latter has happened – A preprint and video are now available for the paper Micro-Rendering for Scalable, Parallel Final Gathering. It shares many authors (including the first) with one of the most interesting papers from last year’s SIGGRAPH Asia conference, Imperfect Shadow Maps for Efficient Computation of Indirect Illumination. Last year’s paper proposed a way to efficiently compute indirect shadowing by rendering a very large number of very low-quality shadowmaps, using a coarse point-based scene representation and some clever hole-filling. This year’s paper extends this occlusion technique to support full global illumination. Some of the same authors were recently responsible for another notable extension of an occlusion method (SSAO in this case) to global illumination.

No preprint or technical report, but promising paper titles: Approximating Subdivision Surfaces with Gregory Patches for Hardware Tessellation and Real-Time Parallel Hashing on the GPU.

Looking at this list and last year’s accepted papers, SIGGRAPH Asia seems to be more accepting of real-time rendering papers than the main SIGGRAPH conference. Combined with the strong courses program, it’s shaping up to be a very good conference this year.

The authors of the second paper, “A Layered, Heterogeneous Reflectance Model for Acquiring and Rendering Human Skin” have also written severalimportantpapers on skin reflectance, focused more on simulating physical processes from first principles. They model human skin as a collection of heterogeneous scattering layers separated by infinitesimally thin heterogeneous absorbing layers. They design their model for efficient GPU evaluation, similar to NVIDIA’s approach mentioned above (one of this paper’s authors also worked on the NVIDIA skin demo). “Efficient” here is a relative term, since their model is too complex to be real-time on current hardware, and as presented is probably too complicated for game use. However, ideas gleaned from this paper are likely to be useful for skin rendering in games. The authors also present a protocol for measuring the parameters of their model

Pixar’s Renderman rendering package is based on the REYES rendering pipeline (an acronym for the humble phrase “Render Everything You Ever Saw”). Most film studios use Pixar’s Renderman, and many others use renderers operating on similar principles. A close reading of the original REYES paper shows a pipeline which was designed to be extremely efficient (it had to be, to run on 1980’s hardware!) and produce very high quality images. I have long thought that this pipeline is a good fit for graphics hardware (given some minor changes or an increase in generality), and is perhaps a better fit to today’s dense scenes than the traditional triangle pipeline. A paper to be published in SIGGRAPH Asia this year describes a GPU implementation of the subdivision stages of the REYES pipeline, which is a key step towards a full GPU REYES implementation. They use CUDA for the subdivision stages, and then pass the resulting micropolygons to a traditional rendering pass. Although combining CUDA and traditional rendering in this manner introduces performance problems, newer APIs such as DX11 compute shaders have been designed to perform well under such conditions. Of course, this algorithm would be a great fit for Larrabee.

I found this paper on Ke-Sen Huang‘s SIGGRAPH Asia preprint page. Ke-Sen performs an invaluable service to the community by providing links to preprints of papers from all the major graphics-related conferences. This preprint page is all the more impressive when you realize that SIGGRAPH Asia has not even published a list of accepted papers yet!

After taking another look at my recent post on 2008 conferences, I thought I would give some context on the various graphics conferences for people who are not familiar with them.

There are a handful of large, international conferences which cover the entire field of computer graphics:

The SIGGRAPHannual conference (technically the “International Conference on Computer Graphics and Interactive Techniques”) is the great-granddaddy of graphics conferences. It’s been around since 1974, and is by far the largest conference devoted to graphics. It has historically been attended mostly by academics and people working in film production, and most papers are not about real-time techniques. In recent years the conference has been making an effort to attract more attendees and speakers from the game industry. The quality of the papers tends to be quite high, and many of them are relevant, even the ones discussing offline techniques often have interesting stuff in them. Besides the papers, there are also courses (called “classes” this year) which are very good. In particular, the excellent (but somewhat verbosely-named) “Advances in Real-Time Rendering in 3D Graphics and Games” class has been presented for the last few years and has very good and relevant presentations from leading real-time graphics practitioners. Many of the classes on film production rendering techniques also have a surprisingly large amount of material relevant for real-time rendering. The Computer Animation Festival (which has this year been expanded to a full-scale film festival) showcases the best CG of the year and is always fun to watch. Although SIGGRAPH has so far always been held in the continental United States (often alternating between west coast and non-west coast locations), in 2011 it will be held in Vancouver, British Columbia.

SIGGRAPH Asia is a new arrival on the scene, being held for the first time this year. It is held in winter and is intended be one of three main “tripod” graphics conferences (with the North American SIGGRAPH conference in the summer, and the Eurographics conference newly moved to the spring). Spreading them evenly throughout the year in this way can enable researchers to submit work when it is ready and not wait for the SIGGRAPH submission deadline – or at least such is the theory. In the past, the existence of other conferences did not prevent most researchers from submitting their work to SIGGRAPH first, but perhaps this will change.

The annual Eurographics conference is the third “major graphics conference”. As its name would suggest, it is held in Europe every year, usually in beautiful locations such as Vienna, Prague, and Crete. The quality of the papers is usually quite high, though it also tends to have mostly non-real-time papers (perhaps even more so than SIGGRAPH).

Graphics Interface is the largest and oldest of these (it is roughly as old as the SIGGRAPH annual conference, and indeed claims to be “the oldest continuously-scheduled conference in the field”). It has always been held in Canada. It tends to have a strong HCI (Human-Computer Interaction) component, as well as some good real-time rendering papers.

Pacific Graphics (more properly “The Pacific Conference on Computer Graphics and Applications”) has been held in locations such as Tokyo, Taipei, Maui, and Macao. The papers are typically of high quality, and have included some important real-time rendering papers. It will be interesting to see how Pacific Graphics fares now that SIGGRAPH Asia has arrived on the scene.

WSCG is a Central European graphics conference. It has had some interesting real-time papers. Unlike the other conferences, the full proceedings of WSCG are freely available.

AFRIGRAPH is another relatively recent regional conference. It has been held in Cape Town, South Africa since 2001.

Besides the generic graphics conferences, there are many conferences focusing on specific subfields of graphics. The ones of most interest to real-time rendering practitioners and researchers are:

EGSR (“Eurographics Symposium on Rendering”) is a relatively large conference focused on all aspects of rendering, both offline and real-time. Some of the most important real-time rendering papers have been published through this conference.

I3D (“Symposium on Interactive 3D Graphics and Games”) has been around for about twenty years, although it has been an annual conference only for the past few years (and has added the “and Games” part of its title more recently still). I’ve attended it twice, it is a nice, small conference. The papers are a mix of HCI and real-time rendering papers, some of which have been quite important to the field.

Graphics Hardware (more properly, the SIGGRAPH/Eurographics Conference on Graphics Hardware) alternates between the USA (where it is co-located with SIGGRAPH) and Europe (where it used to be co-located with Eurographics – since Eurographics was moved to the spring it has been co-located with EGSR). In theory, the papers there should only be of interest to people designing graphics hardware but in practice many of the papers are of great interest to people writing software as well.

Like Graphics Hardware, the Symposium on Computer Animation is also held jointly by SIGGRAPH and Eurographics. It similarly alternates between the USA and Europe. Although technically not a rendering conference, the field of computer animation is in practice strongly linked to rendering (in particular real-time rendering) so it is of interest.

NPAR (or “Symposium on Non-Photorealistic Animation and Rendering”) is another joint SIGGRAPH/Eurographics conference. It is devoted to the rapidly growing field of non-photorealistic or stylized rendering. The first few conferences were held in Annecy, France but it was held in San Diego in 2007 and seems likely to alternate from now on.

Although the Symposium on Geometry Processing is also a joint effort between SIGGRAPH and Eurographics, it has only been held in Europe so far. Geometry processing is another topic which is strongly linked to rendering.

For the past three years the fast-growing field of interactive ray tracing has had its own conference, IRT (or “Symposium on Interactive Ray Tracing”). It is jointly held by IEEE and Eurographics, and alternates between the USA and Europe.

GDC (or “Game Developers Conference”) is another conference of interest to real-time rendering practitioners. Unlike the previously mentioned conferences, which are run by nonprofit professional organizations like ACM, IEEE, and Eurographics, GDC is run by Think Services, which is a for-profit corporation. It is really more like a trade show than an academic conference, and the presentations do not undergo a strict peer-review process. Much of the material relates to non-graphics topics like gameplay and audio design. Nevertheless, there is much interesting material on real-time rendering presented there by game and graphics hardware developers. Although GDC is held in San Francisco, the GDC brand has recently expanded to cover conferences in Texas, China, and France.

Anyone interested in the field of real-time rendering would be well-advised to attend one of these conferences if possible. If not, the printed proceedings can be purchased for reasonable prices and most are available through various digital libraries. Better still, many of the papers (as well as class notes and other materials) can be found on the web for free – Ke-Sen Huang’s excellent homepage makes for a good starting point.